The present invention relates to the field of power regulators and more particularly switching regulators and methods.
Buck mode switching regulators can be used to reduce a total current consumed when a load circuit is operated at a voltage less than that of the power source. Buck mode switching regulators are discussed, for example, at pages 6-21 through 6-23 of the ARRL Handbook published by The American Radio Relay League as well as in the data sheet published by Vishay Siliconix entitled xe2x80x9cSMP Controller For High Performance Processor Power Suppliesxe2x80x9d, Santa Clara, Calif., pages 1-16, Jan. 25, 1999. Both of these references are hereby incorporated herein by reference.
In particular, a buck mode switching regulator can be used in a radiotelephone to regulate power provided from a battery to a transceiver. The buck mode switching regulator can thus reduce a current consumed when the transceiver is actively transmitting and receiving radiotelephone communications thereby decreasing battery drain. During stand-by operations when the transceiver is not actively transmitting and/or receiving radiotelephone communications, however, the buck mode switching regulator may continue to draw current to control the switching. Accordingly, the buck mode switching regulator may undesirably increase current consumption during stand-by operations. Accordingly, there continues to exist a need in the art for switching regulators that can reduce current consumption during stand-by operations.
It is another object of the present invention to provide power controllers, methods, and radiotelephones that can reduce current consumption and battery drain.
These and other objects can be provided according to the present invention by a power controller including a switch and a switching controller. In particular, the switch is coupled between a power source input and a load output wherein the switch is switched on and off responsive to an input signal. The switching controller is coupled to the switch wherein the switching controller generates the input signal so that the switch is switched on and off to provide a regulated power output to the load output during active load operations and so that the switch is maintained closed to couple the power source to the load output without switching to provide an unregulated power output during stand-by load operations. The power controller of the present invention can thus be used in a radiotelephone to provide the regulated power output to a transceiver during active transceiver operations, and to provide the unregulated power output to the transceiver during stand-by transceiver operations. Accordingly, current consumed by the switching controller during stand-by operations can be reduced without significantly increasing the current consumed by the transceiver.
More particularly, the power controller can include a disable switch coupled between the power supply input and the switching controller. This disable switch can be maintained closed during active load operations so that power is provided to the switching controller, and the disable switch can be maintained open during stand-by load operations so that power is not provided to the switching controller during stand-by operations. Accordingly, current consumed by the switching controller is reduced during stand-by operations. Moreover, the switch can be a p-channel MOSFET, and the input signal generated by the switching controller can go to a low logic level when the disable switch is maintained open during stand-by operations thereby closing the switch to provide the unregulated power output during stand-by operations.
In addition, the switch can include an active switch and a bypass switch coupled in parallel between the power supply input and the load output wherein the active switch is switched on and off to provide the regulated power output to the load output during active load operations while the bypass switch is maintained open. The bypass switch is maintained closed during stand-by operations to couple the power source to the load output without switching to provide the unregulated power output during stand-by operations.
The power controllers, radiotelephones, and methods of the present invention can thus provide reduced current consumption during both active and stand-by operations. Accordingly, power consumption and battery drain can be reduced.